The invention is used in the field of manufacture of high-frequency integrated circuits. During the manufacture or at the end of the manufacture of high-frequency integrated circuits, the chips carrying these circuits must have the possibility of being tested in a simple and especially very precise manner.
Now it is very difficult to carry out the test directly on the integrated circuit chip. On the other hand, in the field of high frequencies, it is not possible to transport the test signals through simple wires connected to the input/output contacts of the chip. The signals must imperatively be transported through high-frequency lines having a given characteristic impedance.
Therefore, the integrated circuit chip is positioned on an auxiliary support which comprises a plurality of high-frequency lines having a known impedance. The input/output contacts of the chip are connected to one of the ends of these lines, while the measuring apparatus intended to record the results of the tests are connected on the other end of these lines by means of conventional coaxial lines having an adapted characteristic impedance.
A testing apparatus for integrated circuits is known from U.S. Pat. No. 3,882,597. However, although this document clearly puts the problem of the contacts and connections between the circuit to be tested and the testing apparatus, it does not state any solution for testing a high-frequency circuit whose signals are transported by means of high-frequency lines.
More particularly this apparatus cannnot be adapted to the use of tests including high-frequency lines because the measurement could not be effected due to the fact that the coupling between the high-frequency lines used to connect the integrated circuit to the coaxial connectors connected to the measuring apparatus depends upon the pressure between the mass of the apparatus and the mass surfaces of the high-frequency lines. If the pressure of the measuring apparatus on the mass surfaces of the lines is not adequate, the coupling between these lines is too strong and the measurements are distorted.